I want to sell Bitcoin automatically and immediately after I receive it.
Is there any exchange site has this feature?
You can use one of the Bitcoin exchanges and using their API, create something with the following logic:
while True:
current_balance = get_balance("BTC")
if current_balance > 0:
crypto_exchange.sell_market_order(current_balance)
print("Sold %s" % current_balance)
break
else:
time.sleep(60)
This would automatically sell your crypto as soon as its confirmed as an active balance on the exchange and it would "hedge" your crypto exposure in the process.
I expect that any exchange will require that deposit transactions (i.e. sent from the global Bitcoin network, not from another account within the exchange) have to be confirmed before the coins can be sold or traded. Otherwise, the exchange is vulnerable to double-spend attacks where a customer deposits coins, sells them, withdraws the cash, and then reverses the deposit transaction.
A common requirement is 6 confirmations, meaning that you will have to wait until your transaction is included in a block (which takes at least about 10 minutes on average, longer if the transaction fee you paid is too low) plus an additional 50 minutes on average.
So the answer is no, you should not expect to be able to sell Bitcoin immediately after you receive it.
Yeah.. there are a lot of websites that allow you to sell Bitcoin for USD.
Here are a few: